Foot and ankle injuries usually involve damage to ligaments either through hyperextension or extension beyond normal limitations, and through extension of the ligament in unintended direction as will occur upon abnormal movement of adjacent bones of the ankle and foot with respect to one another. The foot is composed of some 26 bones held together by small ligaments. Large tarsal bones make up the back half of the foot, while metatarsal bones connect the toes and comprise the front of the foot. The longitudinal arch of the foot runs from the heel through the end of the toes. The transverse arch of the foot runs across the tip of the metatarsal bones from the large to the small toe. The ankle joint is the complex articulation joint of the fibula and tibia with the ankle bone or talus and the tarsal bones. The outer ankle knob or lateral malleolus is at the lower end of the fibula. The inner ankle knob or medial malleolus is at the lower end of the tibia. These are held together by the tibial-fibular ligaments to form the top half of the ankle joint or the receptacle known as a mortice which is occupied by the talus. The talus is held by more ligaments. The ankle joint is meant to move only in one direction, flexture and extension or flexing and extending the foot up and down. Side to side movement of the foot and normal twisting motion occurs in the talo-calcaneal joint which lies just below the true ankle joint.
The ligament system holding the bones in proper relationship is particularly susceptable to injury during traumatic activity such as engaging in very active sports. For this reason, persons engaged in such activity usually wear protective gear such as an ankle wrap or an ankle brace. The object of such gear is to restrain the ankle and foot from abnormal rotational movement and from normal extension movement beyond undue limitation without unduly inhibiting normal foot movement so as to impede engagement in the particular acitivity.